pcpu_balance_workfn() unconditionally calls pcpu_balance_free(),
pcpu_reclaim_populated(), pcpu_balance_populated() and
pcpu_balance_free() again.

Each call to pcpu_balance_free() and pcpu_reclaim_populated() will
cause at least one acquisition of the pcpu_lock. So even if the
balancing was scheduled because of a failed atomic allocation,
pcpu_lock will be acquired at least 4 times. This obviously
increases the contention on the pcpu_lock.

To optimize the scheme let's grab the pcpu_lock on the upper level
(in pcpu_balance_workfn()) and keep it generally locked for the whole
duration of the scheduled work, but release conditionally to perform
any slow operations like chunk (de)population and creation of new
chunks.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Tom reported this finding from clang 10's static analysis [1].

Due to the way the code is written, it will always see a successful loop
iteration. Instead of setting an initial value, check that it was set
instead with BUG_ON() because 0 units per allocation is bogus.

[1] https://lore.kernel.org/lkml/20210515180817.1751084-1-trix@redhat.com/Reported-by: Tom Rix <trix@redhat.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

The current implementation of the memcg accounting of the percpu
memory is based on the idea of having two separate sets of chunks for
accounted and non-accounted memory. This approach has an advantage
of not wasting any extra memory for memcg data for non-accounted
chunks, however it complicates the code and leads to a higher chunks
number due to a lower chunk utilization.

Instead of having two chunk types it's possible to declare all* chunks
memcg-aware unless the kernel memory accounting is disabled globally
by a boot option. The size of objcg_array is usually small in
comparison to chunks themselves (it obviously depends on the number of
CPUs), so even if some chunk will have no accounted allocations, the
memory waste isn't significant and will likely be compensated by
a higher chunk utilization. Also, with time more and more percpu
allocations will likely become accounted.

* The first chunk is initialized before the memory cgroup subsystem,
  so we don't know for sure whether we need to allocate obj_cgroups.
  Because it's small, let's make it free for use. Then we don't need
  to allocate obj_cgroups for it.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Introduce a new mem_cgroup_kmem_disabled() helper, similar to
mem_cgroup_disabled(), to check whether the kernel memory accounting
is off. A user could disable it using a boot option to eliminate
some associated costs.

The helper can be used outside of memcontrol.c to dynamically disable
the kmem-related code. The returned value is stable after the kernel
initialization is finished.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

cgroup_memory_nosocket, cgroup_memory_nokmem and cgroup_memory_noswap
are initialized during the kernel initialization and never change
their value afterwards.

cgroup_memory_nosocket, cgroup_memory_nokmem are written only from
cgroup_memory(), which is marked as __init.

cgroup_memory_noswap is written from setup_swap_account() and
mem_cgroup_swap_init(), both are marked as __init.

Mark all three variables as __ro_after_init.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

The sparse tool complains as follows:

mm/percpu.c:138:5: warning:
 symbol 'pcpu_free_slot' was not declared. Should it be static?

This symbol is not used outside of percpu.c, so marks it static.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

From Roman ("percpu: partial chunk depopulation"):
In our [Facebook] production experience the percpu memory allocator is
sometimes struggling with returning the memory to the system. A typical
example is a creation of several thousands memory cgroups (each has
several chunks of the percpu data used for vmstats, vmevents,
ref counters etc). Deletion and complete releasing of these cgroups
doesn't always lead to a shrinkage of the percpu memory, so that
sometimes there are several GB's of memory wasted.

The underlying problem is the fragmentation: to release an underlying
chunk all percpu allocations should be released first. The percpu
allocator tends to top up chunks to improve the utilization. It means
new small-ish allocations (e.g. percpu ref counters) are placed onto
almost filled old-ish chunks, effectively pinning them in memory.

This patchset solves this problem by implementing a partial depopulation
of percpu chunks: chunks with many empty pages are being asynchronously
depopulated and the pages are returned to the system.

To illustrate the problem the following script can be used:
--

cd /sys/fs/cgroup

mkdir percpu_test
echo "+memory" > percpu_test/cgroup.subtree_control

cat /proc/meminfo | grep Percpu

for i in `seq 1 1000`; do
    mkdir percpu_test/cg_"${i}"
    for j in `seq 1 10`; do
	mkdir percpu_test/cg_"${i}"_"${j}"
    done
done

cat /proc/meminfo | grep Percpu

for i in `seq 1 1000`; do
    for j in `seq 1 10`; do
	rmdir percpu_test/cg_"${i}"_"${j}"
    done
done

sleep 10

cat /proc/meminfo | grep Percpu

for i in `seq 1 1000`; do
    rmdir percpu_test/cg_"${i}"
done

rmdir percpu_test
--

It creates 11000 memory cgroups and removes every 10 out of 11.
It prints the initial size of the percpu memory, the size after
creating all cgroups and the size after deleting most of them.

Results:
  vanilla:
    ./percpu_test.sh
    Percpu:             7488 kB
    Percpu:           481152 kB
    Percpu:           481152 kB

  with this patchset applied:
    ./percpu_test.sh
    Percpu:             7488 kB
    Percpu:           481408 kB
    Percpu:           135552 kB

The total size of the percpu memory was reduced by more than 3.5 times.

This patch:

This patch implements partial depopulation of percpu chunks.

As of now, a chunk can be depopulated only as a part of the final
destruction, if there are no more outstanding allocations. However
to minimize a memory waste it might be useful to depopulate a
partially filed chunk, if a small number of outstanding allocations
prevents the chunk from being fully reclaimed.

This patch implements the following depopulation process: it scans
over the chunk pages, looks for a range of empty and populated pages
and performs the depopulation. To avoid races with new allocations,
the chunk is previously isolated. After the depopulation the chunk is
sidelined to a special list or freed. New allocations prefer using
active chunks to sidelined chunks. If a sidelined chunk is used, it is
reintegrated to the active lists.

The depopulation is scheduled on the free path if the chunk is all of
the following:
  1) has more than 1/4 of total pages free and populated
  2) the system has enough free percpu pages aside of this chunk
  3) isn't the reserved chunk
  4) isn't the first chunk
If it's already depopulated but got free populated pages, it's a good
target too. The chunk is moved to a special slot,
pcpu_to_depopulate_slot, chunk->isolated is set, and the balance work
item is scheduled. On isolation, these pages are removed from the
pcpu_nr_empty_pop_pages. It is constantly replaced to the
to_depopulate_slot when it meets these qualifications.

pcpu_reclaim_populated() iterates over the to_depopulate_slot until it
becomes empty. The depopulation is performed in the reverse direction to
keep populated pages close to the beginning. Depopulated chunks are
sidelined to preferentially avoid them for new allocations. When no
active chunk can suffice a new allocation, sidelined chunks are first
checked before creating a new chunk.
Signed-off-by: Roman Gushchin <guro@fb.com>
Co-developed-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Tested-by: Pratik Sampat <psampat@linux.ibm.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

This prepares for adding a to_depopulate list and sidelined list after
the free slot in the set of lists in pcpu_slot.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Factor out the pcpu_check_block_hint() helper, which will be useful
in the future. The new function checks if the allocation can likely
fit within the contig hint.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

__pcpu_balance_workfn() became fairly big and hard to follow, but in
fact it consists of two fully independent parts, responsible for
the destruction of excessive free chunks and population of necessarily
amount of free pages.

In order to simplify the code and prepare for adding of a new
functionality, split it in two functions:

  1) pcpu_balance_free,
  2) pcpu_balance_populated.

Move the taking/releasing of the pcpu_alloc_mutex to an upper level
to keep the current synchronization in place.
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Since the commit 3e54097b ("percpu: manage chunks based on
contig_bits instead of free_bytes") chunks are sorted based on the
size of the biggest continuous free area instead of the total number
of free bytes. Update the corresponding comment to reflect this.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Pull btrfs fix from David Sterba:
 "One more patch that we'd like to get to 5.12 before release.

  It's changing where and how the superblock is stored in the zoned
  mode. It is an on-disk format change but so far there are no
  implications for users as the proper mkfs support hasn't been merged
  and is waiting for the kernel side to settle.

  Until now, the superblocks were derived from the zone index, but zone
  size can differ per device. This is changed to be based on fixed
  offset values, to make it independent of the device zone size.

  The work on that got a bit delayed, we discussed the exact locations
  to support potential device sizes and usecases. (Partially delayed
  also due to my vacation.) Having that in the same release where the
  zoned mode is declared usable is highly desired, there are userspace
  projects that need to be updated to recognize the feature. Pushing
  that to the next release would make things harder to test"

* tag 'for-5.12-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zoned: move superblock logging zone location

Pull locking fixlets from Ingo Molnar:
 "Two minor fixes: one for a Clang warning, the other improves an
  ambiguous/confusing kernel log message"

* tag 'locking-urgent-2021-04-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Address clang -Wformat warning printing for %hd
  lockdep: Add a missing initialization hint to the "INFO: Trying to register non-static key" message

Pull x86 fixes from Borislav Petkov:

 - Fix the vDSO exception handling return path to disable interrupts
   again.

 - A fix for the CE collector to return the proper return values to its
   callers which are used to convey what the collector has done with the
   error address.

* tag 'x86_urgent_for_v5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/traps: Correct exc_general_protection() and math_error() return paths
  RAS/CEC: Correct ce_add_elem()'s returned values

Pull percpu fix from Dennis Zhou:
 "This contains a fix for sporadically failing atomic percpu
  allocations.

  I only caught it recently while I was reviewing a new series [1] and
  simultaneously saw reports by btrfs in xfstests [2] and [3].

  In v5.9, memcg accounting was extended to percpu done by adding a
  second type of chunk. I missed an interaction with the free page float
  count used to ensure we can support atomic allocations. If one type of
  chunk has no free pages, but the other has enough to satisfy the free
  page float requirement, we will not repopulate the free pages for the
  former type of chunk. This led to the sporadically failing atomic
  allocations"

Link: https://lore.kernel.org/linux-mm/20210324190626.564297-1-guro@fb.com/ [1]
Link: https://lore.kernel.org/linux-mm/20210401185158.3275.409509F4@e16-tech.com/ [2]
Link: https://lore.kernel.org/linux-mm/CAL3q7H5RNBjCi708GH7jnczAOe0BLnacT9C+OBgA-Dx9jhB6SQ@mail.gmail.com/ [3]

* 'for-5.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu: make pcpu_nr_empty_pop_pages per chunk type

Pull SCSI fixes from James Bottomley:
 "Seven fixes, all in drivers.

  The hpsa three are the most extensive and the most problematic: it's a
  packed structure misalignment that oopses on ia64 but looks like it
  would also oops on quite a few non-x86 architectures.

  The pm80xx is a regression and the rest are bug fixes for patches in
  the misc tree"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: scsi_transport_srp: Don't block target in SRP_PORT_LOST state
  scsi: target: iscsi: Fix zero tag inside a trace event
  scsi: pm80xx: Fix chip initialization failure
  scsi: ufs: core: Fix wrong Task Tag used in task management request UPIUs
  scsi: ufs: core: Fix task management request completion timeout
  scsi: hpsa: Add an assert to prevent __packed reintroduction
  scsi: hpsa: Fix boot on ia64 (atomic_t alignment)
  scsi: hpsa: Use __packed on individual structs, not header-wide

Pull powerpc fixes from Michael Ellerman:
 "Some some more powerpc fixes for 5.12:

   - Fix an oops triggered by ptrace when CONFIG_PPC_FPU_REGS=n

   - Fix an oops on sigreturn when the VDSO is unmapped on 32-bit

   - Fix vdso_wrapper.o not being rebuilt everytime vdso.so is rebuilt

  Thanks to Christophe Leroy"

* tag 'powerpc-5.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/vdso: Make sure vdso_wrapper.o is rebuilt everytime vdso.so is rebuilt
  powerpc/signal32: Fix Oops on sigreturn with unmapped VDSO
  powerpc/ptrace: Don't return error when getting/setting FP regs without CONFIG_PPC_FPU_REGS

Merge tag 'driver-core-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
 "Here is a single driver core fix for 5.12-rc7 to resolve a reported
  problem that caused some devices to lockup when booting. It has been
  in linux-next with no reported issues"

* tag 'driver-core-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: Fix locking bug in deferred_probe_timeout_work_func()

Pull USB/Thunderbolt fixes from Greg KH:
 "Here are a few small USB and Thunderbolt driver fixes for 5.12-rc7 for
  reported issues:

   - thunderbolt leaks and off-by-one fix

   - cdnsp deque fix

   - usbip fixes for syzbot-reported issues

  All have been in linux-next with no reported problems"

* tag 'usb-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usbip: synchronize event handler with sysfs code paths
  usbip: vudc synchronize sysfs code paths
  usbip: stub-dev synchronize sysfs code paths
  usbip: add sysfs_lock to synchronize sysfs code paths
  thunderbolt: Fix off by one in tb_port_find_retimer()
  thunderbolt: Fix a leak in tb_retimer_add()
  usb: cdnsp: Fixes issue with dequeuing requests after disabling endpoint

Pull i2c fixes from Wolfram Sang:
 "A mixture of driver and documentation bugfixes for I2C"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: imx: mention Oleksij as maintainer of the binding docs
  i2c: exynos5: correct top kerneldoc
  i2c: designware: Adjust bus_freq_hz when refuse high speed mode set
  i2c: hix5hd2: use the correct HiSilicon copyright
  i2c: gpio: update email address in binding docs
  i2c: imx: drop me as maintainer of binding docs
  i2c: stm32f4: Mundane typo fix
  I2C: JZ4780: Fix bug for Ingenic X1000.
  i2c: turn recovery error on init to debug

Moves the location of the superblock logging zones. The new locations of
the logging zones are now determined based on fixed block addresses
instead of on fixed zone numbers.

The old placement method based on fixed zone numbers causes problems when
one needs to inspect a file system image without access to the drive zone
information. In such case, the super block locations cannot be reliably
determined as the zone size is unknown. By locating the superblock logging
zones using fixed addresses, we can scan a dumped file system image without
the zone information since a super block copy will always be present at or
after the fixed known locations.

Introduce the following three pairs of zones containing fixed offset
locations, regardless of the device zone size.

  - primary superblock: offset   0B (and the following zone)
  - first copy:         offset 512G (and the following zone)
  - Second copy:        offset   4T (4096G, and the following zone)

If a logging zone is outside of the disk capacity, we do not record the
superblock copy.

The first copy position is much larger than for a non-zoned filesystem,
which is at 64M.  This is to avoid overlapping with the log zones for
the primary superblock. This higher location is arbitrary but allows
supporting devices with very large zone sizes, plus some space around in
between.

Such large zone size is unrealistic and very unlikely to ever be seen in
real devices. Currently, SMR disks have a zone size of 256MB, and we are
expecting ZNS drives to be in the 1-4GB range, so this limit gives us
room to breathe. For now, we only allow zone sizes up to 8GB. The
maximum zone size that would still fit in the space is 256G.

The fixed location addresses are somewhat arbitrary, with the intent of
maintaining superblock reliability for smaller and larger devices, with
the preference for the latter. For this reason, there are two superblocks
under the first 1T. This should cover use cases for physical devices and
for emulated/device-mapper devices.

The superblock logging zones are reserved for superblock logging and
never used for data or metadata blocks. Note that we only reserve the
two zones per primary/copy actually used for superblock logging. We do
not reserve the ranges of zones possibly containing superblocks with the
largest supported zone size (0-16GB, 512G-528GB, 4096G-4112G).

The zones containing the fixed location offsets used to store
superblocks on a non-zoned volume are also reserved to avoid confusion.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Pull clk fixes from Stephen Boyd:
 "Here's the latest pile of clk driver and clk framework fixes for this
  release:

   - Two clk framework fixes for a long standing issue in
     clk_notifier_{register,unregister}() where we used a pointer that
     was for a struct containing a list head when there was no container
     struct

   - A compile warning fix for socfpga that's good to have

   - A double free problem with devm registered fixed factor clks

   - One last fix to the Qualcomm camera clk driver to use the right clk
     ops so clks don't get stuck and stop working because the firmware
     takes them for a ride"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: fixed: fix double free in resource managed fixed-factor clock
  clk: fix invalid usage of list cursor in unregister
  clk: fix invalid usage of list cursor in register
  clk: qcom: camcc: Update the clock ops for the SC7180
  clk: socfpga: fix iomem pointer cast on 64-bit

Merge tag 'perf-tools-fixes-for-v5.12-2020-04-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tool fixes from Arnaldo Carvalho de Melo:

 - Fix wrong LBR block sorting in 'perf report'

 - Fix 'perf inject' repipe usage when consuming perf.data files

 - Avoid potential buffer overrun when decoding ARM SPE hardware tracing
   packets, bug found using a fuzzer

* tag 'perf-tools-fixes-for-v5.12-2020-04-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf arm-spe: Avoid potential buffer overrun
  perf report: Fix wrong LBR block sorting
  perf inject: Fix repipe usage

Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: mm (kasan, gup, pagecache,
  and kfence), MAINTAINERS, mailmap, nds32, gcov, ocfs2, ia64, and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS
  kfence, x86: fix preemptible warning on KPTI-enabled systems
  lib/test_kasan_module.c: suppress unused var warning
  kasan: fix conflict with page poisoning
  fs: direct-io: fix missing sdio->boundary
  ia64: fix user_stack_pointer() for ptrace()
  ocfs2: fix deadlock between setattr and dio_end_io_write
  gcov: re-fix clang-11+ support
  nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff
  mm/gup: check page posion status for coredump.
  .mailmap: fix old email addresses
  mailmap: update email address for Jordan Crouse
  treewide: change my e-mail address, fix my name
  MAINTAINERS: update CZ.NIC's Turris information

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.12-rc7, including fixes from can, ipsec,
  mac80211, wireless, and bpf trees.

  No scary regressions here or in the works, but small fixes for 5.12
  changes keep coming.

  Current release - regressions:

   - virtio: do not pull payload in skb->head

   - virtio: ensure mac header is set in virtio_net_hdr_to_skb()

   - Revert "net: correct sk_acceptq_is_full()"

   - mptcp: revert "mptcp: provide subflow aware release function"

   - ethernet: lan743x: fix ethernet frame cutoff issue

   - dsa: fix type was not set for devlink port

   - ethtool: remove link_mode param and derive link params from driver

   - sched: htb: fix null pointer dereference on a null new_q

   - wireless: iwlwifi: Fix softirq/hardirq disabling in
     iwl_pcie_enqueue_hcmd()

   - wireless: iwlwifi: fw: fix notification wait locking

   - wireless: brcmfmac: p2p: Fix deadlock introduced by avoiding the
     rtnl dependency

  Current release - new code bugs:

   - napi: fix hangup on napi_disable for threaded napi

   - bpf: take module reference for trampoline in module

   - wireless: mt76: mt7921: fix airtime reporting and related tx hangs

   - wireless: iwlwifi: mvm: rfi: don't lock mvm->mutex when sending
     config command

  Previous releases - regressions:

   - rfkill: revert back to old userspace API by default

   - nfc: fix infinite loop, refcount & memory leaks in LLCP sockets

   - let skb_orphan_partial wake-up waiters

   - xfrm/compat: Cleanup WARN()s that can be user-triggered

   - vxlan, geneve: do not modify the shared tunnel info when PMTU
     triggers an ICMP reply

   - can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

   - can: uapi: mark union inside struct can_frame packed

   - sched: cls: fix action overwrite reference counting

   - sched: cls: fix err handler in tcf_action_init()

   - ethernet: mlxsw: fix ECN marking in tunnel decapsulation

   - ethernet: nfp: Fix a use after free in nfp_bpf_ctrl_msg_rx

   - ethernet: i40e: fix receiving of single packets in xsk zero-copy
     mode

   - ethernet: cxgb4: avoid collecting SGE_QBASE regs during traffic

  Previous releases - always broken:

   - bpf: Refuse non-O_RDWR flags in BPF_OBJ_GET

   - bpf: Refcount task stack in bpf_get_task_stack

   - bpf, x86: Validate computation of branch displacements

   - ieee802154: fix many similar syzbot-found bugs
       - fix NULL dereferences in netlink attribute handling
       - reject unsupported operations on monitor interfaces
       - fix error handling in llsec_key_alloc()

   - xfrm: make ipv4 pmtu check honor ip header df

   - xfrm: make hash generation lock per network namespace

   - xfrm: esp: delete NETIF_F_SCTP_CRC bit from features for esp
     offload

   - ethtool: fix incorrect datatype in set_eee ops

   - xdp: fix xdp_return_frame() kernel BUG throw for page_pool memory
     model

   - openvswitch: fix send of uninitialized stack memory in ct limit
     reply

  Misc:

   - udp: add get handling for UDP_GRO sockopt"

* tag 'net-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (182 commits)
  net: fix hangup on napi_disable for threaded napi
  net: hns3: Trivial spell fix in hns3 driver
  lan743x: fix ethernet frame cutoff issue
  net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
  net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits
  net: dsa: lantiq_gswip: Don't use PHY auto polling
  net: sched: sch_teql: fix null-pointer dereference
  ipv6: report errors for iftoken via netlink extack
  net: sched: fix err handler in tcf_action_init()
  net: sched: fix action overwrite reference counting
  Revert "net: sched: bump refcount for new action in ACT replace mode"
  ice: fix memory leak of aRFS after resuming from suspend
  i40e: Fix sparse warning: missing error code 'err'
  i40e: Fix sparse error: 'vsi->netdev' could be null
  i40e: Fix sparse error: uninitialized symbol 'ring'
  i40e: Fix sparse errors in i40e_txrx.c
  i40e: Fix parameters in aq_get_phy_register()
  nl80211: fix beacon head validation
  bpf, x86: Validate computation of branch displacements for x86-32
  bpf, x86: Validate computation of branch displacements for x86-64
  ...

Pull io_uring fixes from Jens Axboe:
 "Two minor fixups for the reissue logic, and one for making sure that
  unbounded work is canceled on io-wq exit"

* tag 'io_uring-5.12-2021-04-09' of git://git.kernel.dk/linux-block:
  io-wq: cancel unbounded works on io-wq destroy
  io_uring: fix rw req completion
  io_uring: clear F_REISSUE right after getting it

When LATENCYTOP, LOCKDEP, or FAULT_INJECTION_STACKTRACE_FILTER is
enabled and ARCH_WANT_FRAME_POINTERS is disabled, Kbuild gives a warning
such as:

  WARNING: unmet direct dependencies detected for FRAME_POINTER
    Depends on [n]: DEBUG_KERNEL [=y] && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS [=n] || MCOUNT [=n]
    Selected by [y]:
    - LATENCYTOP [=y] && DEBUG_KERNEL [=y] && STACKTRACE_SUPPORT [=y] && PROC_FS [=y] && !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86

Depending on ARCH_WANT_FRAME_POINTERS causes a recursive dependency
error.  ARCH_WANT_FRAME_POINTERS is to be selected by the architecture,
and is not supposed to be overridden by other config options.

Link: https://lkml.kernel.org/r/20210329165329.27994-1-julianbraha@gmail.comSigned-off-by: Julian Braha <julianbraha@gmail.com>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Necip Fazil Yildiran <fazilyildiran@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

On systems with KPTI enabled, we can currently observe the following
warning:

  BUG: using smp_processor_id() in preemptible
  caller is invalidate_user_asid+0x13/0x50
  CPU: 6 PID: 1075 Comm: dmesg Not tainted 5.12.0-rc4-gda4a2b1a5479-kfence_1+ #1
  Hardware name: Hewlett-Packard HP Pro 3500 Series/2ABF, BIOS 8.11 10/24/2012
  Call Trace:
   dump_stack+0x7f/0xad
   check_preemption_disabled+0xc8/0xd0
   invalidate_user_asid+0x13/0x50
   flush_tlb_one_kernel+0x5/0x20
   kfence_protect+0x56/0x80
   ...

While it normally makes sense to require preemption to be off, so that
the expected CPU's TLB is flushed and not another, in our case it really
is best-effort (see comments in kfence_protect_page()).

Avoid the warning by disabling preemption around flush_tlb_one_kernel().

Link: https://lore.kernel.org/lkml/YGIDBAboELGgMgXy@elver.google.com/
Link: https://lkml.kernel.org/r/20210330065737.652669-1-elver@google.comSigned-off-by: Marco Elver <elver@google.com>
Reported-by: Tomi Sarvela <tomi.p.sarvela@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Local `unused' is intentionally unused - it is there to suppress
__must_check warnings.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/202104050216.HflRxfJm-lkp@intel.com
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When page poisoning is enabled, it accesses memory that is marked as
poisoned by KASAN, which leas to false-positive KASAN reports.

Suppress the reports by adding KASAN annotations to unpoison_page()
(poison_page() already has them).

Link: https://lkml.kernel.org/r/2dc799014d31ac13fd97bd906bad33e16376fc67.1617118501.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I encountered a hung task issue, but not a performance one.  I run DIO
on a device (need lba continuous, for example open channel ssd), maybe
hungtask in below case:

  DIO:						Checkpoint:
  get addr A(at boundary), merge into BIO,
  no submit because boundary missing
						flush dirty data(get addr A+1), wait IO(A+1)
						writeback timeout, because DIO(A) didn't submit
  get addr A+2 fail, because checkpoint is doing

dio_send_cur_page() may clear sdio->boundary, so prevent it from missing
a boundary.

Link: https://lkml.kernel.org/r/20210322042253.38312-1-jack.qiu@huawei.com
Fixes: b1058b98 ("direct-io: submit bio after boundary buffer is added to it")
Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ia64 has two stacks:

 - memory stack (or stack), pointed at by by r12

 - register backing store (register stack), pointed at by
   ar.bsp/ar.bspstore with complications around dirty
   register frame on CPU.

In [1] Dmitry noticed that PTRACE_GET_SYSCALL_INFO returns the register
stack instead memory stack.

The bug comes from the fact that user_stack_pointer() and
current_user_stack_pointer() don't return the same register:

  ulong user_stack_pointer(struct pt_regs *regs) { return regs->ar_bspstore; }
  #define current_user_stack_pointer() (current_pt_regs()->r12)

The change gets both back in sync.

I think ptrace(PTRACE_GET_SYSCALL_INFO) is the only affected user by
this bug on ia64.

The change fixes 'rt_sigreturn.gen.test' strace test where it was
observed initially.

Link: https://bugs.gentoo.org/769614 [1]
Link: https://lkml.kernel.org/r/20210331084447.2561532-1-slyfox@gentoo.orgSigned-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The following deadlock is detected:

  truncate -> setattr path is waiting for pending direct IO to be done (inode->i_dio_count become zero) with inode->i_rwsem held (down_write).

  PID: 14827  TASK: ffff881686a9af80  CPU: 20  COMMAND: "ora_p005_hrltd9"
   #0  __schedule at ffffffff818667cc
   #1  schedule at ffffffff81866de6
   #2  inode_dio_wait at ffffffff812a2d04
   #3  ocfs2_setattr at ffffffffc05f322e [ocfs2]
   #4  notify_change at ffffffff812a5a09
   #5  do_truncate at ffffffff812808f5
   #6  do_sys_ftruncate.constprop.18 at ffffffff81280cf2
   #7  sys_ftruncate at ffffffff81280d8e
   #8  do_syscall_64 at ffffffff81003949
   #9  entry_SYSCALL_64_after_hwframe at ffffffff81a001ad

dio completion path is going to complete one direct IO (decrement
inode->i_dio_count), but before that it hung at locking inode->i_rwsem:

   #0  __schedule+700 at ffffffff818667cc
   #1  schedule+54 at ffffffff81866de6
   #2  rwsem_down_write_failed+536 at ffffffff8186aa28
   #3  call_rwsem_down_write_failed+23 at ffffffff8185a1b7
   #4  down_write+45 at ffffffff81869c9d
   #5  ocfs2_dio_end_io_write+180 at ffffffffc05d5444 [ocfs2]
   #6  ocfs2_dio_end_io+85 at ffffffffc05d5a85 [ocfs2]
   #7  dio_complete+140 at ffffffff812c873c
   #8  dio_aio_complete_work+25 at ffffffff812c89f9
   #9  process_one_work+361 at ffffffff810b1889
  #10  worker_thread+77 at ffffffff810b233d
  #11  kthread+261 at ffffffff810b7fd5
  #12  ret_from_fork+62 at ffffffff81a0035e

Thus above forms ABBA deadlock.  The same deadlock was mentioned in
upstream commit 28f5a8a7 ("ocfs2: should wait dio before inode lock
in ocfs2_setattr()").  It seems that that commit only removed the
cluster lock (the victim of above dead lock) from the ABBA deadlock
party.

End-user visible effects: Process hang in truncate -> ocfs2_setattr path
and other processes hang at ocfs2_dio_end_io_write path.

This is to fix the deadlock itself.  It removes inode_lock() call from
dio completion path to remove the deadlock and add ip_alloc_sem lock in
setattr path to synchronize the inode modifications.

[wen.gang.wang@oracle.com: remove the "had_alloc_lock" as suggested]
  Link: https://lkml.kernel.org/r/20210402171344.1605-1-wen.gang.wang@oracle.com

Link: https://lkml.kernel.org/r/20210331203654.3911-1-wen.gang.wang@oracle.comSigned-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

LLVM changed the expected function signature for llvm_gcda_emit_function()
in the clang-11 release.  Users of clang-11 or newer may have noticed
their kernels producing invalid coverage information:

  $ llvm-cov gcov -a -c -u -f -b <input>.gcda -- gcno=<input>.gcno
  1 <func>: checksum mismatch, \
    (<lineno chksum A>, <cfg chksum B>) != (<lineno chksum A>, <cfg chksum C>)
  2 Invalid .gcda File!
  ...

Fix up the function signatures so calling this function interprets its
parameters correctly and computes the correct cfg checksum.  In
particular, in clang-11, the additional checksum is no longer optional.

Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d
Link: https://lkml.kernel.org/r/20210408184631.1156669-1-ndesaulniers@google.comReported-by: Prasad Sodagudi <psodagud@quicinc.com>
Tested-by: Prasad Sodagudi <psodagud@quicinc.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: <stable@vger.kernel.org>	[5.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit cb9f753a ("mm: fix races between swapoff and flush dcache")
updated flush_dcache_page implementations on several architectures to
use page_mapping_file() in order to avoid races between page_mapping()
and swapoff().

This update missed arch/nds32 and there is a possibility of a race
there.

Replace page_mapping() with page_mapping_file() in nds32 implementation
of flush_dcache_page().

Link: https://lkml.kernel.org/r/20210330175126.26500-1-rppt@kernel.org
Fixes: cb9f753a ("mm: fix races between swapoff and flush dcache")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Greentime Hu <green.hu@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When we do coredump for user process signal, this may be an SIGBUS signal
with BUS_MCEERR_AR or BUS_MCEERR_AO code, which means this signal is
resulted from ECC memory fail like SRAR or SRAO, we expect the memory
recovery work is finished correctly, then the get_dump_page() will not
return the error page as its process pte is set invalid by
memory_failure().

But memory_failure() may fail, and the process's related pte may not be
correctly set invalid, for current code, we will return the poison page,
get it dumped, and then lead to system panic as its in kernel code.

So check the poison status in get_dump_page(), and if TRUE, return NULL.

There maybe other scenario that is also better to check the posion status
and not to panic, so make a wrapper for this check, Thanks to David's
suggestion(<david@redhat.com>).

[akpm@linux-foundation.org: s/0/false/]
[yaoaili@kingsoft.com: is_page_poisoned() arg cannot be null, per Matthew]

Link: https://lkml.kernel.org/r/20210322115233.05e4e82a@alex-virtual-machine
Link: https://lkml.kernel.org/r/20210319104437.6f30e80d@alex-virtual-machineSigned-off-by: Aili Yao <yaoaili@kingsoft.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aili Yao <yaoaili@kingsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Update Nick & Nadia's old addresses.

Link: https://lkml.kernel.org/r/20210406134036.GQ2531743@casper.infradead.orgSigned-off-by: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

jcrouse at codeaurora.org has started bouncing.  Redirect to a more
permanent address.

Link: https://lkml.kernel.org/r/20210325143700.1490518-1-jordan@cosmicpenguin.netSigned-off-by: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: Alexander Lobakin <alobakin@pm.me>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change my e-mail address to kabel@kernel.org, and fix my name in
non-code parts (add diacritical mark).

Link: https://lkml.kernel.org/r/20210325171123.28093-2-kabel@kernel.orgSigned-off-by: Marek Behún <kabel@kernel.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>